Attorney General Jeff Sessions was one of President Donald Trump’s early supporters. But their relationship has become more complicated. (Bill Clark/CQ Roll Call)

When Attorney General Jeff Sessions announced last week that the Trump administration would end the Deferred Action for Childhood Arrivals program, he was also signaling a new act in one of the summer’s most riveting political dramas.

Sessions had been considered a dead man walking since mid-July, when Trump began berating him in interviews and on social media for his decision to recuse himself from the investigation of Russian meddling in the 2016 election. Yet here he was, on a podium, serving as a proxy for the president as he announced a controversial policy decision that Sessions has sought for years — and on which Trump was reportedly wavering.